Recently, according to increasing the network traffic in the IMS, the role of Network Management System (NMS) is very important because of limited network resource. NMS can perform two kinds of routing ways with the capability of static or dynamic routing. The way of A dynamic routing is more efficient than static routing one because it can make the flow of traffic changeful among nodes in the IMS. Therefore, in this paper, we suggest a management function of NMS, using a dynamic routing algorithm for managing the CSCFs in the IMS. And then we analyze the algorithm by measuring the performance of PoC, one of the prominent application services to be deployed in the IMS.